宽带激光抑制交叉光束能量转移的实验演示
Experimental demonstration of broadband-laser suppression of cross-beam energy transfer
- Shanghai Institute of Laser Plasma, China Academy of Engineering Physics（上海激光等离子体研究所，中国工程物理研究院）
- Institute of Applied Physics and Computational Mathematics（应用物理与计算数学研究所）
- Joint Laboratory of High Power Laser and Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences（高功率激光与物理联合实验室，中国科学院上海光学精密机械研究所）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
实验证明宽带激光能有效抑制直接驱动ICF中的交叉光束能量转移，降低反射光返回，减少能量逃逸。
AI中文摘要：
在直接驱动惯性约束聚变（ICF）中，交叉光束能量转移（CBET）将入射激光能量的相当大一部分重定向出等离子体。我们报告了宽带激光减少CBET增强的反射光返回的实验演示，该实验在低相干昆吾激光装置上进行，使用两束交叉光束，带宽为0.6%，能量高达550J，强度约为2.6×10^14 W/cm^2。耦合光线追踪模型表明，窄带反射光的强CBET放大在宽带照明下大大减弱。在两束正交光束的对称入射条件下，总散射能量分数从7.57%降至4.64%；在非对称入射条件下，将受激布里渊散射（SBS）与镜面反射分开，SBS分数从3.75%降至0.46%，镜面反射分数从约2.2%降至1.3%。这些结果确立了宽带激光作为在直接驱动ICF中减少通过CBET增强反射的能量逃逸的有效且经实验验证的方法。
英文摘要：
In direct-drive inertial confinement fusion (ICF), cross-beam energy transfer (CBET) redirects a significant fraction of the incident laser energy out of the plasma. We report the experimental demonstration that broadband lasers reduce CBET-enhanced reflected-light return, performed at the low-coherence Kunwu laser facility with two crossed beams of 0.6% bandwidth and up to 550J at $\sim$2.6$\times$10$^{14}$ W/cm$^{2}$. A coupled ray-tracing model shows that the strong CBET amplification of narrowband reflected light is much weaker under broadband illumination. In symmetric incidence condition of two orthogonal beams, the total fractional scattered energy decreases from 7.57% to 4.64%; in asymmetric incidence condition, which separates stimulated Brillouin scattering (SBS) from specular reflection, the SBS fraction decreases from 3.75% to 0.46% and the specular-reflection fraction decreases from approximately 2.2% to 1.3%. These results establish broadband lasers as an effective, experimentally validated approach to reducing energy escape through CBET-enhanced reflection in direct-drive ICF.
